Returning Force/Direction to zero

I'm working on a space-sim.

Many of the projectiles have rigid bodies, and have force upon collision/impact. However since there's no gravity, objects will continue to fly forever and it interferes with flight controls.

What would be a good way to counter this? Like, returning the ship's state slowly back to it's origin.

Or, how can I figure out what force is being placed on an object, to know how to slowly counter it?